// use std::collections::HashMap;

fn assert_alphametic_solution_eq(puzzle: &str, solution: &[(char, u8)]) {
    let answer = solve(puzzle);
    let solution: HashMap<char, u8> = solution.iter().cloned().collect();
    assert_eq!(answer, Some(solution));
}

#[test]
fn test_with_three_letters() {
    assert_alphametic_solution_eq("I + BB == ILL", &[('I', 1), ('B', 9), ('L', 0)]);
}

#[test]
//#[ignore]
fn test_must_have_unique_value_for_each_letter() {
    let answer = solve("A == B");
    assert_eq!(answer, None);
}

#[test]
//#[ignore]
fn test_leading_zero_solution_is_invalid() {
    let answer = solve("ACA + DD == BD");
    assert_eq!(answer, None);
}

#[test]
//#[ignore]
fn test_puzzle_with_four_letters() {
    assert_alphametic_solution_eq("AS + A == MOM", &[('A', 9), ('S', 2), ('M', 1), ('O', 0)]);
}

#[test]
//#[ignore]
fn test_puzzle_with_six_letters() {
    assert_alphametic_solution_eq(
        "NO + NO + TOO == LATE",
        &[('N', 7), ('O', 4), ('T', 9), ('L', 1), ('A', 0), ('E', 2)],
    );
}

#[test]
//#[ignore]
fn test_puzzle_with_seven_letters() {
    assert_alphametic_solution_eq(
        "HE + SEES + THE == LIGHT",
        &[
            ('E', 4),
            ('G', 2),
            ('H', 5),
            ('I', 0),
            ('L', 1),
            ('S', 9),
            ('T', 7),
        ],
    );
}

#[test]
//#[ignore]
fn test_puzzle_with_eight_letters() {
    assert_alphametic_solution_eq(
        "SEND + MORE == MONEY",
        &[
            ('S', 9),
            ('E', 5),
            ('N', 6),
            ('D', 7),
            ('M', 1),
            ('O', 0),
            ('R', 8),
            ('Y', 2),
        ],
    );
}

#[test]
//#[ignore]
fn test_puzzle_with_ten_letters() {
    assert_alphametic_solution_eq(
        "AND + A + STRONG + OFFENSE + AS + A + GOOD == DEFENSE",
        &[
            ('A', 5),
            ('D', 3),
            ('E', 4),
            ('F', 7),
            ('G', 8),
            ('N', 0),
            ('O', 2),
            ('R', 1),
            ('S', 6),
            ('T', 9),
        ],
    );
}
